Object file system for Mahara.
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README.md

mahara-module_objectfs

A remote object storage file system for Mahara. Intended to provide a plug-in that can be installed and configured to work with any supported remote object storage solution. Currently supports both AWS S3 and Azure Blob Storage.

This plug-in requires either mahara-module_aws or mahara-module_azure to function.

Use cases

There are a number of different ways you can use this plug in. See Recommended use case settings for recommended settings for each one.

Offloading large and old files to save money

Disk can be expensive, so a simple use case is we simply want to move some of the largest and oldest files off local disk to somewhere cheaper. But we still want the convenience and performance of having the majority of files local, especially if you are hosting on-prem where the latency or bandwidth to the remote filesystem may not be great.

Sharing files across maharas to save disk

Many of our clients have multiple mahara instances, and there is much duplicated content across instances. By pointing multiple maharas at the same remote filesystem, and not allowing deletes, then large amounts of content can be de-duplicated.

Sharing files across environments to save time

Some of our clients maharas are truly massive. We also have multiple environments for various types of testing, and often have ad hoc environments created on demand. Not only do we not want to have to store duplicated files, but we also want refreshing data to new environments to be as fast as possible.

Using this plugin we can configure production to have full read write to the remote filesystem and store the vast bulk of content remotely. In this setup the latency and bandwidth isn't an issue as they are colocated. The local filedir on disk would only consist of small or fast churning files. A refresh of the production data back to a staging environment can be much quicker now as we skip the sitedir clone completely and stage is simple configured with readonly access to the production filesystem. Any files it creates would only be written to it's local filesystem which can then be discarded when next refreshed.

Installation

  1. If not on Mahara 18.04, backport the file system API. See Backporting
  2. Setup your remote object storage. See Remote object storage setup
  3. Clone this repository into module/objectfs
  4. Clone either mahara-module_aws into module/aws or mahara-module_azure into module/azure
  5. Install the plugins through the mahara GUI.
  6. Configure the plugin. See Mahara configuration
  7. Place one of the following in htdocs/config.php depending on your choice of remote storage (Azure or s3):

For AWS S3:

$cfg->externalfilesystem = array(
   "includefilepath" => "module/objectfs/classes/s3_file_system.php",
   "class" => "module_objectfs\\s3_file_system"
);

For Azure:

$cfg->externalfilesystem = array(
    "includefilepath" => "module/objectfs/classes/azure_file_system.php",
    "class" => "module_objectfs\\azure_file_system"
);

Currently supported object stores

Roadmap

There is support for more object stores planed, in particular enabling Openstack deployments.

Amazon S3

Amazon S3 bucket setup

  • Create an Amazon S3 bucket.
  • The AWS Users access policy should mirror the policy listed below.
  • Replace 'bucketname' with the name of your S3 bucket.
{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": ["s3:ListBucket"],
      "Resource": ["arn:aws:s3:::bucketname"]
    },
    {
      "Effect": "Allow",
      "Action": [
        "s3:PutObject",
        "s3:GetObject",
        "s3:DeleteObject"
      ],
      "Resource": ["arn:aws:s3:::bucketname/*"]
    }
  ]
}

Azure Blob Storage

Azure Storage container guide with the CLI

It is possible to install the Azure CLI locally to administer the storage account. The Azure CLI can be obtained here.

Visit the Online Azure Portal or use the Azure CLI to obtain the storage account keys. These keys are used to setup the container, configure an access policy and acquire a Shared Access Signature that has Read and Write capabilities on the container.

It will be assumed at this point that a resource group and blob storage account exists.

  • Obtain the account keys.
az login

az storage account keys list \
  --resource-group <resource_group_name> \
  --account-name <storage_account_name>
  • Create a private container in a storage account.
az storage container create \
    --name <container_name> \
    --account-name <storage_account_name> \
    --account-key <storage_account_key> \
    --public-access off \
    --fail-on-exist
  • Create a stored access policy on the containing object.
az storage container policy create \
    --account-name <storage_account_name> \
    --account-key <storage_account_key> \
    --container-name <container_name> \
    --name <policy_name> \
    --start <YYYY-MM-DD> \
    --expiry <YYYY-MM-DD> \
    --permissions rw

# Start and Expiry are optional arguments.
  • Generates a shared access signature for the container. This is associated with a policy.
az storage container generate-sas \
    --account-name <storage_account_name> \
    --account-key <storage_account_key> \
    --name <container_name> \
    --policy <policy_name> \
    --output tsv
  • If you wish to revoke access to the container, remove the policy which will invalidate the SAS.
az storage container policy delete \
    --account-name <storage_account_name> \
    --account-key <storage_account_key> \
    --container-name <container_name>
    --name <policy_name>

Mahara configuration

Go to Administration -> Extensions -> objectfs. Descriptions for the various settings are as follows:

General Settings

  • Enable file transfer tasks: Enable or disable the object file system tasks which move files between the filedir and remote object storage.
  • Maximum task runtime: Background tasks handle the transfer of objects to and from remote object storage. This setting controls the maximum runtime for all object transfer related tasks.
  • Prefer remote objects: If a file is stored both locally and in remote object storage, read from remote. This is setting is mainly for testing purposes and introduces overhead to check the location.

File Transfer settings

These settings control the movement of files to and from object storage.

  • Minimum size threshold (KB): Minimum size threshold for transferring objects to remote object storage. If objects are over this size they will be transfered.
  • Minimum age: Minimum age that a object must exist on the local filedir before it will be considered for transfer.
  • Delete local objects: Delete local objects once they are in remote object storage after the consistency delay.
  • Consistency delay: How long an object must have existed after being transfered to remote object storage before they are a candidate for deletion locally.

Storage File System Selection

This settings controls which object storage type to use, depending on installed modules the current choices are \module_objectfs\s3_filesystem and \module_objectfs\azure_file_system

Azure Blob Storage Settings

Azure specific settings

  • Account name: The name of the storage account created in Azure
  • Container name: The name of the container in Azure that will store the blobs
  • Share access signature: The Shared Access Signature that you created for access to the container

Amazon S3 settings

S3 specific settings

  • Key: AWS credential key
  • Secret: AWS credential secret
  • Bucket: S3 bucket name to store files in
  • AWS region: AWS API endpoint region to use.

Backporting

If you are on an older mahara then you can backport the necessary API's in order to support this plugin. Use with caution!

Warm thanks

Thanks to Microsoft for sponsoring the Azure Storage implementation.

Microsoft

Crafted by Catalyst IT

This plugin was developed by Catalyst IT Australia:

https://www.catalyst-au.net/

Catalyst IT

Contributing and support

Issues, and pull requests using github are welcome and encouraged!

https://github.com/catalyst/mahara-module_objectfs/issues

If you would like commercial support or would like to sponsor additional improvements to this plugin please contact us:

https://www.catalyst-au.net/contact-us